Organic light emitting display device with second metal layer contacting first metal layer at power supply line

ABSTRACT

The present disclosure discloses an organic light emitting display device having a substrate including an active area configured to display an image and an inactive area configured to surround the active area; a power supply line in the inactive area; a first planarization layer on a layer where the power supply line is disposed on; a first metal layer on the first planarization layer and in contact with the power supply line; a second planarization layer configured to planarize an upper portion of the first metal layer; and a second metal layer, on the second planarization layer, and in contact with the first metal layer and a cathode of an organic light emitting diode, so that an improved arrangement of signals lines in the inactive area where conductive lines are efficiently arranged in a limited space at an edge portion of the substrate in order to realize a narrow bezel configuration and have a signal line structure capable of supplying stable power to various components.

CROSS REFERENCE TO RELATED APPLICATION

This application claims the benefit of the Korean Patent Application No.10-2016-0143699 filed on Oct. 31, 2016, which is hereby incorporated byreference in its entirety as if fully set forth herein.

BACKGROUND Field of the Disclosure

The present disclosure relates to a display device, and moreparticularly, to an organic light emitting display device.

Description of the Background

Image display device that realizes information on the screen is beingdeveloped to be thinner, lighter, and more portable and to have higherperformance. Therefore, an organic light emitting display device fordisplaying an image by controlling the amount of light emitted from theorganic light emitting device is gaining popularity.

The organic light emitting device is advantageous in that it can be madethin, due to its self-luminous characteristics using a thin lightemitting layer between electrodes. A typical organic light emittingdisplay device has a structure in which a pixel driving circuit and anorganic light emitting element are formed on a substrate, and lightemitted from the organic light emitting element passes through thesubstrate or the barrier layer to display an image.

Since the organic light emitting display device is implemented without aseparate light source, it can be readily implemented as a flexibledisplay device. A flexible material such as plastic or metal foil can beused as a substrate of an organic light emitting display device.

As the size and high resolution of the organic light emitting displaydevice have been advanced in recent years, the required number of signallines has increased, but the space for arranging a greater number ofsignal lines has become insufficient. Thus, it is an important task tosecure sufficient space for accommodating various elements and theirelectric wiring. Furthermore, a method of efficiently arranging variousparts and elements is being studied.

SUMMARY

An aspect of the present disclosure is to provide an organic lightemitting display device and a signal line arrangement structure appliedto the organic light emitting display device.

It should be noted that other aspects of the present disclosure are notlimited to the above and additional aspects of the present disclosurewill be apparent to those skilled in the art from the followingdescriptions.

The organic light emitting display device may include a substrateincluding an active area configured to display an image and an inactivearea configured to surround the active area, a power supply line in theinactive area, a first planarization layer on a layer where the powersupply line is disposed on, a first metal layer on the firstplanarization layer and in contact with the power supply line, a secondplanarization layer configured to planarize an upper portion of thefirst metal layer, and a second metal layer, on the second planarizationlayer, and in contact with the first metal layer and a cathode of anorganic light emitting diode. The details of other aspects are includedin the detailed description and accompanying drawings.

According to the aspects of the present disclosure, there is provided anorganic light emitting display with improved arrangement of signalslines in an inactive area. More specifically, the aspects of the presentdisclosure can provide an organic light emitting display in whichconductive lines are efficiently arranged in a limited space at an edgeportion of the substrate. Accordingly, the organic light emittingdisplay device according to the aspects of the present disclosure canrealize a narrow bezel configuration. Furthermore, the aspects of thepresent disclosure can provide an organic light emitting display havinga signal line structure capable of supplying stable power to variouscomponents.

It should be noted that the effects of the present disclosure are notlimited to those described above and other effects of the presentdisclosure are included in the following descriptions.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and other aspects, features and other advantages of thepresent disclosure will be more clearly understood from the followingdetailed description taken in conjunction with the accompanyingdrawings, in which:

FIG. 1 is a plan view of an organic light emitting display according toan aspect of the present disclosure;

FIG. 2 is a cross-sectional view illustrating a portion of an activearea of an organic light emitting display device according to an aspectof the present disclosure;

FIG. 3 is a cross-sectional view illustrating a portion of an inactivearea of an organic light emitting display according to the related art;

FIG. 4 is a view illustrating a portion of an inactive area of anorganic light emitting display device according to an aspect of thepresent disclosure; and

FIG. 5A and FIG. 5B are views illustrating a portion of an inactive areaof an organic light emitting display device according to another aspectof the present disclosure.

DETAILED DESCRIPTION

Advantages and characteristics of the present disclosure and methods foraccomplishing the same will be more clearly understood from the aspectsdescribed below with reference to the accompanying drawings. However,the present disclosure is not limited to the aspects but may beimplemented in various different forms. The aspects are provided only tocomplete disclosure of the present disclosure and to fully provide aperson having ordinary skill in the art to which the present disclosurepertains and the present disclosure will be defined by the appendedclaims.

The shapes, sizes, ratios, angles, numbers and the like illustrated inthe accompanying drawings for describing the various aspects of thepresent disclosure are merely examples and the present disclosure is notlimited thereto. Like reference numerals generally denote like elementsthroughout the present specification. Further, in the followingdescription, a detailed explanation of known related technologies may beomitted to avoid unnecessarily obscuring the subject matter of thepresent disclosure. The terms such as “including”, “having” and“comprising” used herein are generally intended to allow othercomponents to be added unless the terms are used with the term “only”.Any references to singular may include plural unless expressly statedotherwise. Components are interpreted to include an ordinary error rangeor an ordinary tolerance range even if not expressly stated.

When the positional relationship between two parts is described usingthe terms such as “on”, “above”, “below” and “next”, on or more partsmay be positioned between the two parts unless the terms are used withthe term “immediately” or “directly”. When an element or layer isreferred to as being “on” another element or layer, it may be directlyon the other element or layer, or intervening elements or layers may bepresent. It should be understood when an element is described as being“connected”, “coupled”, or “connected” to another element, the elementmay be directly connected or connected to the other element, but also itcan be interpreted that another element may be “interposed”therebetween, or each element may be “connected”, “coupled”, or“contacted” through another element.

Although the terms “first”, “second” and the like are used fordescribing various components, these components are not confined bythese terms. These terms are merely used for distinguishing onecomponent from the other components. Therefore, a first component to bementioned below may be a second component with respect to the technicalconcepts of the present disclosure.

Since the size and thickness of each component illustrated in thedrawings are represented for the convenience of explanation, the presentdisclosure is not necessarily limited to the illustrated size andthickness of each component. Various aspects of the present disclosurewill be described in detail with reference to the accompanying drawings.

FIG. 1 is a plan view of an organic light emitting display according toan aspect of the present disclosure.

Referring to FIG. 1, an organic light emitting display device 100includes at least an active area A/A having an array of pixels disposedtherein. At least an inactive area I/A may be formed around the activearea. That is, the inactive area may be adjacent to one or more side ofthe active area. In FIG. 1, the inactive area surrounds an active areahaving a rectangular shape. However, the shape of the active area andthe shape and the arrangement of the inactive area adjacent to theactive area are not limited to the flexible display as illustrated inFIG. 1. The active area and the inactive area may be formed to besuitable for designing an electronic device on which the display device100 is implemented. Non-limiting examples of the active area shapes ispentagonal, hexagonal, circular, oval, and the like.

Each pixel in the active area A/A may be associated with a pixel drivingcircuit. The pixel driving circuit may include at least one switchingtransistor and at least one driving transistor. Each pixel drivingcircuit may be electrically connected to a signal line (e.g., a gateline, a data line, and the like) for sending and receiving signals witha gate driver, a data driver, and the like positioned in the inactivearea.

The gate driver and the data driver may be implemented with a thin filmtransistor (TFT) in the inactive area I/A. These drivers may be referredto as gate-in-panel (GIP) due to its implementation in the panel itself.In addition, some components, such as a data driver integrated circuit(IC), may be mounted on a separate printed circuit board, and it may becoupled with a connection interface (e.g., pad, bump, pin, and the like)disposed in the inactive area through a circuit film such as flexibleprinted circuit board (FPCB), chip-on-film (COF) or tape-carrier-package(TCP). The printed circuit (COF, PCB, etc.) may be located behind thedisplay device 100.

The organic light emitting display device 100 may include variousadditional elements for generating various signals or driving pixels inthe active area. Additional elements for driving the pixel may includean inverter circuit, a multiplexer, an electrostatic discharge (ESD)circuit, and the like. The organic light emitting display device 100 mayalso include additional elements associated with functions other thanpixel driving. For example, the organic light emitting display device100 may include additional elements for providing a touch sensingfunction, a user authentication function (e.g., fingerprint scanning), amulti-level pressure sensing function, a tactile feedback function andthe like. The above-mentioned additional elements may be located in theinactive area and/or an external circuit connected to the connectioninterface.

The organic light emitting display device according to the presentdisclosure may include a substrate 101 on which a thin film transistorand an organic light emitting diode are arranged, an encapsulation layer120, a barrier film 140, and the like.

The substrate 101 supports various elements of the organic lightemitting display device 100. The substrate 101 may be formed of atransparent insulating material, for example, glass, plastic, or thelike. The substrate (i.e., array substrate) may also include an elementand a functional layer formed thereon, for example, a switching TFT, adriving TFT connected to the switching TFT, an organic light emittingelement connected to the driving TFT, a passivation layer or the like.

The organic light emitting element is disposed on the substrate 101. Theorganic light emitting element includes an anode, an organic lightemitting layer, and a cathode. The organic light emitting element mayhave a single light emitting layer structure to emit a single colorlight (such as red, green or blue) or may include a plurality of lightemitting layers to emit white light. When the organic light emittingelement emits white light, a color filter or color refiner may furtherbe provided. The organic light emitting element may be formed in thecentral portion of the substrate 101 to correspond to the active area.

The encapsulation layer 120 may cover the organic light emittingelement. The encapsulation layer protects the organic light emittingdevice from external moisture or oxygen. A barrier film may be disposedon the encapsulation layer.

The organic light emitting display device 100 includes a plurality ofpixels, and each pixel may include a plurality of sub-pixels. At thistime, the sub-pixel may be considered to be the minimum unit forexpressing one color.

One sub-pixel may include a plurality of transistors, a capacitor, and aplurality of signal lines. The sub-pixel may be composed of twotransistors and one capacitor (i.e., 2T1C), but it is not limitedthereto and may be implemented as a sub-pixel realized with a structuresuch as 4T1C, 7T1C, 6T2C, and the like. In addition, the sub-pixel maybe implemented to be suitable for the organic light emitting displaydevice 100 of the top emission type.

FIG. 2 is a cross-sectional view illustrating a portion of an activearea of an organic light emitting display device according to an aspectof the present disclosure.

The organic light emitting display device of FIG. 2 has an exemplarystructure in which two planarization layers are formed. In the organiclight emitting display device 100, thin film transistor elements 102,104, 106 and 108, organic light emitting elements 112, 114 and 116 andvarious functional layers are disposed on the substrate (or an arraysubstrate).

The substrate 101 may be a glass or plastic substrate. In the case of aplastic substrate, a polyimide-based material or a polycarbonate-basedmaterial may be used to have flexibility. In particular, polyimide canbe processed under a high-temperature and is a material that can becoated, and thus is widely used as a plastic substrate.

The buffer layer 130 is a functional layer for protecting the electrodeand signal lines from impurities such as alkali ions or the like cameout from the substrate 101 or the lower layers. The buffer layer may beformed of silicon oxide (SiOx), silicon nitride (SiNx), or a multilayerthereof. The buffer layer 130 may include a multi-buffer 131 and/or anactive buffer 132. The multi-buffer 131 may be formed by alternatelystacking silicon nitride (SiNx) and silicon oxide (SiOx), and mayprevent or delay diffusion of moisture and/or oxygen permeated into thesubstrate 101. The active buffer 132 protects the semiconductor layer102 of the transistor and functions to block various kinds of defectsintroduced from the substrate 101. The active buffer 132 may be formedof amorphous silicon (a-Si) or the like.

The thin film transistor may be in the form in which the semiconductorlayer 102, the gate insulating layer 103, the gate electrode 104, theinterlayer insulating layer 105, and the source and drain electrodes 106and 108 are sequentially stacked. The semiconductor layer 102 is locatedon the buffer layer 130. The semiconductor layer 102 may be made ofpolysilicon (p-Si), and in such case, a predetermined region may bedoped with an impurity. In addition, the semiconductor layer 102 may bemade of amorphous silicon (a-Si), or may be made of various organicsemiconductor materials such as pentacene. Further, the semiconductorlayer 102 may be made of an oxide material. The gate insulating layer103 may be formed of an insulating inorganic material such as siliconoxide (SiOx) or silicon nitride (SiNx), or may be formed of aninsulating organic material or the like. The gate electrode 104 may beformed of various conductive materials such as copper (Cu), magnesium(Mg), aluminum (Al), nickel (Ni), chrome (Cr), molybdenum (Mo), tungsten(W) or the like.

The interlayer insulating layer 105 may be formed of an insulatingmaterial such as silicon oxide (SiOx) or silicon nitride (SiNx), or maybe formed of an insulating organic material or the like. A contact holemay be formed by selectively removing portions of the interlayerinsulating film 105 and the gate insulating film 103 so as to expose thesource and drain regions.

The source and drain electrodes 106 and 108 are formed on the interlayerinsulating layer 105 in the form of a single layer or a multi-layeredstructure with an electrode material. A passivation layer composed of aninorganic insulating material may cover the source and drain electrodes106 and 108.

The first planarization layer 107-1 may be on the thin film transistor.The first planarization layer 107-1 protects the thin film transistorand the like and flattens the upper portion thereof. The firstplanarization layer 107-1 may be formed in various shapes and may beformed of at least one among various materials such as acrylic resin,epoxy resin, phenol resin, polyamide resin, polyimide resin, unsaturatedpolyester resin, polyphenylene resin, and polyphenylene sulfide resin,but are not limited thereto.

On the first planarization layer 107-1, various metal layers functionsas signal lines and electrodes may be disposed.

The second planarization layer 107-2 is on the first planarization layer107-1. In this aspect, two planarization layers are implemented due tothe number of various signal lines are increased as the display deviceevolves to achieve higher resolution. Therefore, it is difficult toarrange all the signal lines in a single layer while ensuring theminimum gap between the signal lines, thus, an additional layer isrequired. This extra layer (i.e., second planarization layer) providessufficient room for signal line arrangement, which makes it easier todesign the signal lines/electrodes arrangement. Further, a dielectricmaterial may be used for the planarization layers 107-1 and 107-2,thereby forming capacitances between the planarization layers 107-1 and107-2 and the metal layers.

The organic light emitting element may have a structure in which thefirst electrode 112, the organic light emitting layer 114, and thesecond electrode 116 are sequentially stacked. That is, the organiclight emitting element may be configured as a first electrode 112 formedon the planarization layer 107, an organic light emitting layer 114disposed on the first electrode 112, and a second electrode 116 disposedon the organic light emitting layer 114.

The first electrode 112 may be electrically connected to the drainelectrode 108D of the driving thin film transistor through theconnection electrode 108-2. When the organic light emitting displaydevice 100 is a top emission type, the first electrode 112 may be madeof an opaque conductive material having high reflectivity. For example,the first electrode 112 may be formed of silver (Ag), aluminum (Al),gold (Au), molybdenum (Mo), tungsten (W), chromium (Cr) or alloythereof. The connection electrode 108-2 may be made of the same materialas the source and drain electrodes 106 and 108.

The bank 110 is formed in the region except for the light emittingregion. Accordingly, the bank 110 has a bank opening for exposing thefirst electrode 112 corresponding to the light emitting region. The bank110 may be made of an inorganic insulating material such as a siliconnitride (SiNx), a silicon oxide (SiOx), or an organic insulatingmaterial such as BCB, acrylic resin or imide resin.

The organic light emitting layer 114 is disposed on the first electrode112 which is exposed by the bank 110. The organic light emitting layer114 may include a light emitting layer, an electron injection layer, anelectron transport layer, a hole transport layer, a hole injectionlayer, and the like. One or more of these layers may be combined into asingle layer. Alternatively, one or more functionalities may be combinedinto a particular layer.

The second electrode 116 is disposed on the organic light emitting layer114. When the organic light emitting display device 100 is a topemission type, the second electrode 116 may be a transparent conductivelayer such as indium tin oxide (ITO) or indium zinc oxide (IZO), therebyemitting the light generated in the organic light emitting layer 114 tothe upper portion of the second electrode 116.

The encapsulation layer 120 is on the second electrode 116. Theencapsulation layer 120 provides protection from oxygen and moisturepenetration in order to prevent oxidation of the light emitting elementand the electrode material. When the organic light emitting element isexposed to moisture or oxygen, a pixel shrinkage phenomenon in which alight emitting region is reduced or dark spots in a light emittingregion may occur. The encapsulation layer may be composed of aninorganic film made of glass, metal, aluminum oxide (AlOx) or silicon(Si) based material, or alternatively, an organic film and an inorganicfilm may be alternately laminated. The inorganic film serves to blockpermeation of moisture and oxygen, and the organic film serves toplanarize the surface of the inorganic film. The reason why theencapsulation layer may be formed of a multiple layers is that it makesthe permeation path of moisture and oxygen longer and more complicatedthan a single layer so as to make permeation of moisture and oxygen intothe organic light emitting element more difficult.

The barrier film 140 is disposed on the encapsulation layer 120 toencapsulate the entire substrate 101 including the organic lightemitting element. The barrier film 140 may be a phase difference film oran optically isotropic film. When the barrier film has opticallyisotropic characteristics, the light incident on the barrier film istransmitted as it is without phase delay. Further, an organic film or aninorganic film may be further disposed on the upper or lower surface ofthe barrier film. The organic film or the inorganic film formed on theupper or lower surface of the barrier film serves to protect permeationof moisture or oxygen.

The adhesive layer 145 may be positioned between the barrier film 140and the encapsulation layer 120. The adhesive layer 145 bonds theencapsulation layer 120 and the barrier film 140. The adhesive layer 145may be a thermosetting or natural curing adhesive. For example, theadhesive layer 145 may be made of a material such as B-PSA (Barrierpressure sensitive adhesive). On the barrier film 140, a touch panel(e.g., touch film), a polarizing film, a top cover, and the like may befurther disposed.

FIG. 3 is a cross-sectional view illustrating a portion of an inactivearea of an organic light emitting display according to the related art.

The inactive area I/A may be located outside the active area A/A asillustrated, and a circuit unit (e.g., GIP), power supply line, or thelike may be disposed thereon.

The substrate 301 as illustrated in FIG. 3 may be the same substrate asthe substrate 101 illustrated in FIG. 1 and FIG. 2. Further, theinterlayer insulating layer 305, the buffer layer 330, the bank 310 andthe organic light emitting elements 312, 314 and 316 may be the same asthe interlayer insulating layer 105, the buffer layer 130, the bank 110and the organic light emitting elements 112, 114, and 116, asillustrated in FIG. 1 and FIG. 2, respectively.

On the other hand, the inorganic layer 321-1, the organic layer 322 andthe inorganic layer 321-2 are examples of the encapsulation layer 120 asillustrated in FIG. 2. The passivation layer 309 may be an insulatinglayer covering the signal line 308-1 disposed in the inactive area. Thedam 390 is a structure for controlling the spreading of the organiclayer 322 in the inactive area I/A.

Various circuits, electrodes and signal lines disposed in the inactivearea can be made of the gate metal 304′ and/or the source/drain metal308′. The gate metal 304′ is formed in the same process as the gateelectrode of the TFT, and the source/drain metal 308′ is formed in thesame process with the same material as the source/drain electrode of theTFT.

As illustrated in FIG. 3, the source/drain metal 308′ may be used as apower supply line (e.g., ground voltage (Vss)). The power supply line308′ is connected to the metal layer 312′ and the cathode 316 mayreceive voltage through the connection with the source/drain metal 308′and the metal layer 312′. The metal layer 312′ may contact the powersupply line and may extend along the sidewall of the outermostplanarization layer 307 to contact the cathode 316 on the planarizationlayer 307. The metal layer 312′ may be formed of the same material asthe anode 312 of the organic light emitting diode and formed in the sameprocess.

The typical organic light emitting display device has a planarizationlayer 307 as a single layer in the active area A/A and/or the inactivearea I/A. In such a single planarization layer structure, a circuitportion (e.g., GIP) and a power supply line (e.g., Vss) are arranged onthe same layer on a bezel. That is, the driving circuits 304′and 308″and the power supply line 308′ are disposed on the same layer (e.g., thebuffer layer 305) as illustrated in FIG. 3. In particular, since thepower supply line needs to have a certain area (or a width) in order toreduce the line resistance, thus, such arrangement occupies aconsiderably wide width, which limits the implementation of a narrowbezel.

FIG. 4 is a view illustrating a portion of an inactive area of anorganic light emitting display device according to an aspect of thepresent disclosure.

In the organic light emitting display device as illustrated in FIG. 4, asignal line arrangement structure for implementing a narrow bezel isapplied. Referring to FIG. 4, substantially the same elements asillustrated in FIG. 1 and FIG. 2 are denoted by the same referencenumerals, and redundant descriptions thereof will be omitted.

The inactive area I/A may be located outside the active area A/A asillustrated, and a circuit portion (e.g., GIP), power supply line, orthe like may be disposed thereon. In the illustrated aspect, aplanarization layer is provided with two layers 107-1 and 107-2. This isto accommodate the increased signal lines with respect to the highresolution screen as described above.

The first planarization layer 107-1 flattens (or planarizes) the upperportion of various circuit elements (e.g., thin film transistors,capacitors, conductors, and the like) on the substrate. A passivationlayer 109-1 made of an inorganic material may be disposed between thefirst planarization layer 107-1 and the circuit element. Variousfunctional metal layers 108-2 may be disposed on the first planarizationlayer 107-1. At this time, inorganic layers 109-2 and 109-3 forarranging the metal layers 108-2 may be provided on the firstplanarization layer 107-1. For example, the inorganic layer includes abuffer layer 109-2 and a passivation layer 109-3. The metal layer 108-2may be disposed over the buffer layer 109-2 and covered with apassivation layer 109-3. The metal layer 108-2 may be a metal formed inthe same process as the source and drain electrodes 106 and 108 of thethin film transistor.

The second planarization layer 107-2 is provided on the firstplanarization layer 107-1. The organic light emitting elements 112, 114and 116 may be disposed on the second planarization layer 107-2. At thistime, the metal layers 112 and 112′ connected to the organic lightemitting element may be disposed on the second planarization layer107-2. The metal layer 112′ may be formed of a metal made of the samematerial as the anode 112. At this time, the metal layer 112′ may havean opening(s) for out-gassing of any gas generated in the secondplanarization layer 107-2.

Hereinafter, for convenience of description, the metal layer 108-2 onthe first planarization layer 107-1 is referred to as a first metallayer and a metal layer 112′ on the second planarization layer 107-2 isreferred to as a second metal layer. The first metal layer 108-2 and thesecond metal layer 112′ in the inactive area I/A may configure astructure connecting the power supply line 108-1 and the cathode 116.

The power supply line 108-1 is disposed outside the first planarizationlayer 107-1 and the first metal layer 108-2 contacts the power supplyline 108-1 at the outside the first planarization layer 107-1 and mayextend along (or cover) the outermost sidewall of the firstplanarization layer 107-1. At this time, the first metal layer 108-2 mayhave a line width less than or equal to the width of the power supplyline as described in the structure of the related art as shown in FIG. 3for the purpose of controlling the resistance. That is, the first metallayer 108-2 has a specific width so as to have a resistance lower thanthe structure of the related art when connected to the power supplyline. Therefore, the power supply line 108-1 can be implemented with awidth smaller than that of the related art, so that the inactive areabecomes smaller. The reason for the presence of the metal layerconnected to the power supply line on the first planarization layer107-1 may be regarded as that the power supply line disposed on the sideof the circuit portions 104′ and 108′ is rearranged to the upper portionof the circuit portions 104′ and 108′. Thus, the above structure canreduce the width of the bezel. Also, under the same bezel widthcondition, the above structure can ensure more areas than the relatedart.

On the other hand, the second metal layer 112′ contacts the first metallayer 108-1 and extends inward (i.e., toward the active area) to contactthe cathode 116 of the organic light emitting diode. Thus, the cathode116 can receive voltage through connection with the second metal layer112′. The second metal layer 112′ contacts the first metal layer 108-1at a certain point, that is, at a point where the power supply line108-1 and the first metal layer 108-1 meet. Further, the second metallayer 112′ may extend over the upper surface of the first metal layer108-1 and the outermost sidewall of the second planarization layer 107-2and may contact the cathode 116 at an upper portion of the secondplanarization layer 107-2. The second metal layer 112′ may be formed ofthe same material as the anode 112 of the organic light emitting diodewhich is formed in the same process.

As illustrated in FIG. 4, it is advantageous that the signal line layoutstructure using the two planarization layers can reduce the width of theinactive area (e.g., bezel) or allow a margin for scribing in theperiphery of the display device.

FIG. 5A and FIG. 5B are views illustrating a portion of an inactive areaof an organic light emitting display device according to another aspectof the present disclosure.

Referring to FIG. 5A and FIG. 5B, substantially the same elements asillustrated in FIG. 1, FIG. 2 and FIG. 4 are denoted by the samereference numerals, and redundant descriptions thereof will be omitted.

In another aspect as shown in FIGS. 5A and 5B, the first metal layer108-2 and the second metal layer 112′ configure a structure forconnecting the power supply line 108-1 and the cathode 116, which isdifferent from the aspect of the disclosure shown in FIG. 4. Referringto FIG. 5A, the power supply line 108-1 may be disposed outside thefirst planarization layer 107-1 and the first metal layer 108-2 may bein contact with the power supply line 108-1 at the first point (1),outside of the first planarization layer 107-1, and may extend (orcover) the outermost side wall. At this time, the first metal layer108-2 may extend sufficiently inward to contact the second metal layer112′ at the second point (2). Meanwhile, the first metal layer may havean opening for out-gassing gas generated in the first planarizationlayer 107-1.

On the other hand, the second metal layer 112′ contacts the first metallayer 108-1 and extends inward to contact the cathode 116 at the thirdpoint (3). The cathode 116 may receive voltage through a connection withthe second metal layer 112′. The second metal layer 112′ may alsocontact the first metal layer 108-1 at the first point. The second metallayer 112′ may extend to cover the upper surface of the first metallayer 108-1 and the outermost sidewall of the second planarization layer107-2 so as to contact with the cathode 116 on the second planarizationlayer 107-2.

In the above-described second aspect, the second metal layer 112′contacts with the first metal layer 108-2 at two points (1), (2), sothat a more stable electrical connection can be ensured. FIG. 5B is aplan view of the organic light emitting display device. In the case ofthe second aspect, the first point (1) is the point where the powersupply line 108-1, the first metal layer 108-2 and the second metallayer 112′ contact each other. The second point (2) is a point where thefirst metal layer 108-2 and the second metal layer 112′ contact eachother. The third point (3) is a point where the second metal layer 112′and the cathode 116 contact each other.

If the power supply line 108-1 and the first metal layer 108-2 are madeof the same material, a conductive path is formed as if the first metallayer 108-2 is connected in parallel to two portions of the second metallayer 112′ whereby the overall path resistance can be reduced.Accordingly, such a structure can reduce power supply voltagevariations.

Meanwhile, as an alternative aspect, the second metal layer 112′ may notbe in contact with the first metal layer 108-2 at the first point (1).That is, the second metal layer 112′ is not positioned on the sidewallof the second planarization layer 107-2 but formed only on the upperportion of the second planarization layer 107-2, thus, it may be incontact with the first metal layer 108-2 only at the second point (2).This can be applied when the second metal layer 112′ is a materialhaving a relatively high resistance. In this case, the conductive paththrough the second metal layer, which has a relatively high resistancethan the first metal layer, is shortened, and thus, the fluctuation ofthe power supply can be minimized. In case of the alternative aspect,referring to FIG. 5B, the first point (1) is a point where the powersupply wiring 108-1 and the first metal layer 108-2 are in contact witheach other. The second point (2) is a point where the first metal layer108-2 and the second metal layer 112′ are in contact with each other.The third point (3) is a point where the second metal layer 112′ and thecathode 116 are in contact with each other.

The light-emitting display device according to the aspects of thepresent disclosure can be implemented on a substrate 101 on which anactive area A/A in which an image is displayed and an inactive area I/Asurrounding the active area are defined. The substrate 101 may be aflexible substrate having flexibility. The power supply line 108-1 andthe connection structures 108-2 and 112′ may be disposed in the inactivearea I/A of the substrate 101. The power supply line may be a line forsupplying the ground voltage Vss.

A first planarization layer 107-1 may be formed on a layer where thepower supply line 108-1 is formed and a first metal layer 108-2 may beformed on the first planarization layer 107-1 and is in contact with thepower supply line 108-1. The second planarization layer 107-2 mayflatten (or planarizes) the upper portion of the first metal layer108-2, a second metal layer 112′ is positioned on the secondplanarization layer, and the second metal layer 112′ is in contact withthe first metal layer and the cathode of the organic light emittingdiode. The first metal layer 108-2 may be made of a material having aresistance lower than that of the second metal layer 112′.

The first metal layer 108-2 may contact the power supply line 108-1 fromthe outside of the first planarization layer 107-1. Further, the firstmetal layer 108-2 may cover the sidewall of the first planarizationlayer 107-1 and may extend toward the active area on the firstplanarization layer 107-1. At this time, the first metal layer 108-2 ispositioned above the circuit portion (e.g., GIP circuit) with the firstplanarization layer 107-1 therebetween. The first metal layer 108-2 mayfurther extend toward the active area and may contact the second metallayer 112′ on the first planarization layer 107-1.

On the other hand, the second metal layer may contact with the firstmetal layer 108-2 at a point where the first metal layer 108-2 contactsthe power supply line 108-1, or may contact with the first metal layer108-2 on the first planarization layer 107-1 without directly contactingpower supply line 108-1.

The aspects of the present disclosure can be described as follows:

A display device (100) comprises a substrate having an active area (A/A)including a matrix of pixels and having an inactive area (I/A) adjacentto the active area; and a dual-layer planarization structure (107-1 and107-2), having a first planarization layer (107-1) and a secondplanarization layer (107-2) thereon, over the active area and extendinginto the inactive area. The inactive area has a first region, adjacentto the active area, in which a Gate-In-Panel (GIP) structure (104′) islocated, the GIP structure configured to transfer gate signals to thepixels. Also, the inactive area has a second region, adjacent to thefirst region, in which a power supply line (108-1) is located, the powersupply line configured to transfer voltage to the pixels. The first andsecond regions have an overlapping section that provides a more narrowbezel compared to a conventional bezel in which the first and secondregions have no overlap.

The overlapping section is achieved by having the power supply lineconfigured as a two-metal structure, which includes a first metal layer(108-1, 108″) patterned under the first planarization layer and includesa second metal layer (108-2) on an end portion of the firstplanarization layer.

The second metal layer is in contact with the first metal layer at theend portion of the first planarization layer (i.e., contact point 1 inFIGS. 5A-5B) and the second metal layer extends up the end portion andonto a top surface of the first planarization layer, with an end portionof the second planarization layer covering a portion of the second metallayer at the top surface of the first planarization layer.

The display device may further have an anode metal layer (112′) that ispatterned on the second planarization layer, the anode metal layerhaving a portion extending over the end portions of the first and secondplanarization layers onto the second metal layer, the anode metal layerbeing in contact with the second metal layer via a contact hole throughthe second planarization layer (i.e., contact point 2 in FIGS. 5A-5B).Also, the display device may further have a cathode (116) above thesecond planarization layer in the active area and extending into theinactive area, the cathode being in contact with the anode metal layerat the inactive area (i.e., contact point 3 in FIGS. 5A-5B). Also, thedisplay device may further have one or more dams (190) along an edge ofthe inactive area and spaced apart from the end portions of the firstand second planarization layers. Additionally, the display device mayfurther have a particle cover layer (PCL) (122) covering the active areaand the inactive area up to the dams. Furthermore, at least one amongthe second metal layer and the anode metal layer includes outgassingholes (e.g., as shown in FIGS. 4 and 5A).

The aspects of the present disclosure can also be described as follows:

According to an aspect of the present disclosure, an organic lightemitting display device may include a substrate including an active areaconfigured to display an image and an inactive area configured tosurround the active area, a power supply line in the inactive area, afirst planarization layer on a layer where the power supply line isdisposed on, a first metal layer on the first planarization layer and incontact with the power supply line, a second planarization layerconfigured to planarize an upper portion of the first metal layer, and asecond metal layer, on the second planarization layer, and in contactwith the first metal layer and a cathode of an organic light emittingdiode.

The first metal layer may be in contact with the power supply line at anoutside of the first planarization layer.

The first metal layer may cover a side wall of the first planarizationlayer and extends towards to the active area on the first planarizationlayer.

The first metal layer may be on a circuit unit with the firstplanarization layer interposed therebetween.

The circuit unis may be a gate in panel (GIP) circuit.

The first metal layer may be in contact with the second metal layer onthe first planarization layer.

The second metal layer may be in contact with the first metal layer at apoint where the first metal layer contacts the power supply line.

The second metal layer may contact the first metal layer on the firstplanarization layer without directly contacting the power supply line.

The first metal layer and the second metal layer may include openingsformed to exhaust residual gases of the first planarization layer andthe second planarization.

The power supply line may be a line for supplying a ground voltage(Vss).

The first metal layer may be made of a material having a lowerresistance than the second metal layer.

The substrate may be a flexible substrate.

Although the exemplary aspects of the present disclosure have beendescribed in detail with reference to the accompanying drawings, thepresent disclosure is not limited thereto and may be embodied in manydifferent forms without departing from the technical concept of thepresent disclosure. Therefore, the aspects of the present disclosure areprovided for illustrative purpose only but not intended to limit thetechnical concept of the present disclosure. The features of variousaspects of the present disclosure can be partially or entirely bonded toor combined with each other and can be interlocked and operated intechnically various ways as can be fully understood by a person havingordinary skill in the art and the aspects can be carried outindependently of or in association with each other.

The protective scope of the present disclosure should be construed basedon the following claims and all the technical concepts in the equivalentscope thereof should be construed as falling within the scope of thepresent disclosure.

What is claimed is:
 1. An organic light emitting display devicecomprising: an active area and an inactive area on a substrate, theactive area configured to display an image and an inactive areasurrounding the active area; a power supply line in the inactive area; afirst planarization layer on a layer where the power supply line isdisposed; a first metal layer on the first planarization layer to coveran outermost sidewall of the first planarization layer and in contactwith the power supply line; a second planarization layer planarizing anupper portion of the first metal layer; an organic light emitting diodeon the second planarization layer; a second metal layer on the secondplanarization layer to cover an outermost sidewall of the secondplanarization layer and the upper surface of the first metal layercovering the outermost sidewall of the first planarization layer, and incontact with the first metal layer and a cathode of the organic lightemitting diode; and a bank on the second planarization layer and on thesecond metal layer, and wherein the cathode is disposed on the bank andin contact with the second metal layer via a contact hole formed in thebank.
 2. The organic light emitting display device of claim 1, whereinthe first metal layer is in contact with the power supply line outsidethe first planarization layer.
 3. The organic light emitting displaydevice of claim 2, wherein the first metal layer covers a side wall ofthe first planarization layer and extends towards to the active area onthe first planarization layer.
 4. The organic light emitting displaydevice of claim 3, wherein the first metal layer is disposed on acircuit unit with the first planarization layer interposed therebetween.5. The organic light emitting display device of claim 4, wherein thecircuit unit includes a gate in panel (GIP) circuit.
 6. The organiclight emitting display device of claim 3, wherein the first metal layeris in contact with the second metal layer on the first planarizationlayer.
 7. The organic light emitting display device of claim 3, whereinthe second metal layer is in contact with the first metal layer at apoint where the first metal layer contacts the power supply line.
 8. Theorganic light emitting display device of claim 2, wherein the secondmetal layer contacts the first metal layer on the first planarizationlayer without contacting the power supply line.
 9. The organic lightemitting display device of claim 1, wherein the first metal layer andthe second metal layer include one or more openings to exhaust residualgases from the first planarization layer and the second planarizationlayer.
 10. The organic light emitting display device of claim 1, whereinthe power supply line is a line for supplying a ground voltage.
 11. Theorganic light emitting display device of claim 1, wherein the firstmetal layer is made of a material having a lower resistance than thesecond metal layer.
 12. The organic light emitting display device ofclaim 1, wherein the substrate includes a flexible substrate.